ABSTRACT

The aim of the present research was to investigate the effects of the selective dopamine re-uptake inhibitor GBR 12909 (10 mg/kg, i.p.) on dopaminergic neurotransmission in rat striatum. GBR 12909 increased DA levels in microdialysis samples from freely moving rats. In contrast, administration of GBR 12909 slightly decreased the NSD 1015 (50 mg/kg)--induced DOPA accumulation. This result may be explained as a decrease in DA biosynthesis in response to an increasing amount of DA in the synaptic cleft. Fast-scan cyclic voltammetric monitoring of electrically-evoked DA showed significant changes after the drug in DA re-uptake (Km), but not DA release. In conclusion, our results support the notion, that GBR 12909 is a specific DA uptake inhibitor without any transmitter releasing action.